OLANDIR VERCINO CORREA
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Artigo IPEN-doc 27389 Surface chemistry and semiconducting properties of passive film and corrosion resistance of annealed surgical stainless steel2020 - OLIVEIRA, RODRIGO K. de; CORREA, OLANDIR V.; OLIVEIRA, MARA C.L. de; ANTUNES, RENATO A.ASTM F-139 surgical stainless steel was subjected to annealing treatments at 700 °C for different times. The effect of annealing on the chemical composition of the passive film was evaluated by x-ray photoelectron spectroscopy. The correlation of the surface chemistry with the corrosion behavior and semiconducting properties of the passive film was also investigated. Potentiodynamic polarization tests were conducted in phosphate-buffered solution at 37°C. The semiconducting character of the passive film was assessed by the Mott–Schottky approach. The microstructure of the annealed samples was characterized by optical microscopy. The grain size increased after annealing, but the differences between each annealing condition were not significant and could not be associated with the corrosion behavior of the annealed samples. The corrosion resistance was improved depending on the heat treatment condition due to compositional changes of the passive film upon annealing. The best corrosion properties were observed after annealing for 8 h which was ascribed to Cr2O3, MoO3 and FeO enrichment in the passive film.Artigo IPEN-doc 23600 Influência do tamanho de grão sobre a resistência à corrosão do aço inoxidável AISI 3042016 - TORRES, ANA de A.; CORREA, OLANDIR V.; ANTUNES, RENATO A.Grain size refinement can modify the electrochemical behavior of austenitic stainless steels due the variation of the grain boundaries density. The relationship between grain size and corrosion resistance is not straightforward, motivating several investigations to help clarifying this effect. The aim of the present work was to investigate the effect of grain size on the pitting corrosion resistance of the AISI 304 stainless steel. By exposing samples of this material to different annealing treatments different microstructures with varying grain sizes have been obtained. Potentiodynamic polarization curves were used to evaluate the corrosion behavior of the samples. The results showed that pitting corrosion resistance was increased for the samples with finer grain sizes and this effect is likely due to the formation of a more stable passive film.Artigo IPEN-doc 20836 Effect of laser parameters on the corrosion resistance of the ASTM F139 stainless steel2015 - PIERETTI, EURICO F.; PESSINE, ELISABETE J.; CORREA, OLANDIR V.; ROSSI, WAGNER de; NEVES, MAURICIO D.M. dasArtigo IPEN-doc 10935 Corrosion and cytotoxicity evaluation of AISI 316L stainless steel produced by powder injection molding (PIM) technology2005 - COSTA, I.; ROGERO, S.O.; CORREA, O.V.; KUNIOSHI, C.T.; SAIKI, M.This study investigates the in vitro corrosion and cytotoxicity response of AISI 316L stainless steel produced by powder injection molding (PIM) technology in a solution that simulates physiological fluids (MEM) by electrochemical techniques and neutral red uptake cytotoxicity assay. The results were compared with those of AISI 316L produced by conventional metallurgy. Both steels showed high corrosion resistance and no toxic effect in the cytotoxicity test. The corrosion products were analyzed by instrumental neutron activation analysis (INAA). The surfaces of the alloys were evaluated before and after corrosion test by scanning electron microscopy and a passive behaviour was indicated supporting the results from other techniques.